Rockwell Automation 7000L PowerFlex Medium Voltage AC Drive (C Frame) - Classic Control - Manual (Page 501)

Troubleshooting 7-17
7000 “C” Frame 7000L-UM300I-EN-P – June 2013
FAULT
MESSAGE
FAULT
CODE
DESCRIPTION RECOMMENDED ACTIONS
Motor Heartbeat 167 The DCB-L has detected the loss of the
heartbeat signal from the DCB-M. – Verify DC Control voltages to both DCBs
– Possible Failed DCB – Check LED status
of both boards and compare with table in
the manual – Recycle power and replace
board if necessary
Motor Load Loss 74 The drive has detected a loss of load
condition. This is activated as a fault using
the parameter Load Loss Detect (P199),
and the necessary setpoints are Load Loss
Level (P246), Load Loss Delay (P231), and
Load Loss Speed (P259).
– Verify the parameter settings
– Ensure that the load should not normally
be in an unloaded condition
– This is designed for applications likely to
lose the load (downhole pump – hollow-
shaft motor) and we do not want to run
with the loss of load
Motor Neutral OV 67 The Neutral-to-Ground voltage measured
from the Output Filter Capacitor Neutral
point has exceeded Ground Fault
Overvoltage Trip (P189) for the duration set
in Ground Fault Overvoltage (P190). This
value is displayed in V Motor Neutral
(P347).
– Insulation Failure – Megger the motor
insulation/motor cables/drive insulation to
ground
– Verify the integrity of the output
grounding network if applicable
– Megger the input Isolation Transformer
Secondaries/Input Cables to ground
– Verify Parameter settings are appropriate
for AC Line Reactor or Isolation
Transformer drives
– Verify the integrity of Motor Filter
Capacitors, looking for short circuits or
signs of physical damage. Refer to
Chapter 6 of the User‟s Manual for
detailed instructions on Testing Filter
Capacitors.
Motor OC 21 The measured motor current I Stator (P340)
has exceeded Motor Overcurrent Trip
(P177) for the duration set in Motor
Overcurrent Delay (P178).
Possible Causes:
– Real OC/Transients
– Bad Burden resistor/Current Sensor
Circuit Failure – Check components
– Parameter settings too low compared to
torque limit – Verify Parameter settings
– Current regulator in limit (check line
voltage and Alpha line while running)
Motor OL 65 A Motor Overload condition has been
detected, where the overload condition is
calculated using I Stator(P340) and an
algorithm based on Motor Overload Trip
(P179) as the absolute trip level, Motor
Overload Delay (P180) as the base trip delay,
and Motor Overload Min (P351) as the point
where the overload calculation begins.
– Transient Loading - Check torque limit
and overload settings and Compare
loading to torque settings and trip
settings
– Burden Resistor – Check LEM feedback
and Check the burden resistors